heat sinks - swarthmore · pdf fileheat sinks 1. heat transfer conduction: heat transfer...

C. Sauriol Rev. 1/27/2003 © Heat Sinks

HEAT SINKS 1. HEAT TRANSFER Conduction: heat transfer through and by means of matter not involving motion of the matter. . The amount of heat transfer depends on the thermal conductivity of the material, its cross-section area normal to the direction of the heat flow and the temperature gradient or differential. Convection: heat tranfer by moving matter. The fluid used for convection absorbs the heat by conduction and then moves away carrying the heat within it. Natural convection occurs when the fluid being heated becomes less dense and is pushed away by the cooler fluid which is more dense, and thus produces a natural or unaided flow. Forced convection is accomplished using a fan (air flow) or a pump (liquid flow) and is more efficient than natural convection. Efficiency is proportional to the flow rate (litres/sec or m3/s) of the cooling fluid. Radiation: heat transfer not involving a transport medium or matter. The rate at which a body emits heat in the form of electromagnetic radiation is a function of its temperature and its thermal emissivity. 2. HEAT DISSIPATION IN A TRANSISTOR

BIPOLAR TRANSISTOR

EMITTER COLLECTORBASE

N P N

+- +-VBE VCB

I E

I B

I C

PEB=I E*V BE PCB=I C*V CB

MORE HEAT

PTOTAL = IE VBE + IC VCB _ IE (VBE + VCB) = IE VCE

MOSFET TRANSISTOR

DRAIN SOURCEGATE

P

N N

SUBSTRATE

CHANNEL

CHANNEL MORERESISTIVE, MORE HEAT

P=VDS*I D

+ + + + + + + + + +

In a bipolar transistor most of the heat is generated at the CB junction where the voltage drop is higher. Therefore the collector usually makes a physical contact with the transistor case for better heat transfer to the ambiant air surrounding the case - the metal case is a good heat conductor. In the MOSFET the heat is generated in the channel where the electronic current flows and the majority of that heat will be dissipated near the drain where the channel is pinched and therefore channel resistance at its highest. The drain therefore makes physical contact with the metal case for a more efficient heat transfer to the outside ambient air.


3. THERMAL-ELECTRICAL EQUIVALENTS

Electrical Thermal current source ampere (A) heat source P watt (W)

current ampere (A) power P watt (W) voltage volt (V) temperature T degree celsius (°C)

resistance ohm (Ω) resistance θ (°C/W)

capacitance farad (F) capacitance CT (J/°C) impedance ohm (Ω) transient impedance θ(t) (°C/W)

Thermal resistance: a quantity that represents the amount of opposition to the flow of heat. Thermal resistance is given by:

θ = d

kA=

∆ T

P = T 2 − T 1 P

where d = thickness, A = area, k = thermal conductivity of material, ∆T = temperature change across two planes normal to direction of heat flow, P = power representing the rate of flow of thermal energy (or heat) in Watts or Joules/sec.

T1 T2

d

Energy flowor

energy ratein

Joules/sec

AREA

Thermal capacitance: a quantity that represents the capacity to store heat. Thermal capacitance is given by:

C T = H × M = ∆ E

∆ T

where ∆E is the quantity of heat absorbed in Joules for a temperature rise ∆T, after temperature has stabilised, M = mass of sample material, H = specific heat of material, that is the quantity of thermal energy required to raise the temperature of one gram of material by 1°C. The unit of H is usually in Cal/(gr-°C).

MASS

( M )

THERMALENERGYSTORED

TEMP

(T)

Typical specifications for popular JEDEC metal cases

CASE # TO-3 TO-5 TO-8 TO-18 TO-36 TO-66 TO-220 thermal

resistance(°C/W) 30 150 75 300 25 60 60 thermal capacitance

(J/°C) 6,8 0,58 1,84 - - 2,56 - thermal time constant

(sec) 204 87 138 - - 154 -


4. THERMAL EQUIVALENT CIRCUIT - THERMAL OHM'S LAW

Thermal equivalent circuit

P

TJ TC

TA

θJC

θCA

+ -

+

-

∆T1

∆T2 HEAT SOURCE

Power transistor

SILICON

EB

C

TRANSISTORCASE

If the power dissipation of an electronic component is constant, it will heat up and reach thermal equilibrium, that is the silicon and case temperatures will reach constant levels. Under those conditions, we can use thermal Ohm's law to calculate the steady-state temperatures. Thermal Ohm's law: ∆ T = T J − T A = P × θ tot = P × θ JC + θ CA( ) T J − T C = ∆ T 1 = P × θ JC where TJ is the junction or silicon chip temperature P is the power dissipation TA is the ambiant air temperature θ is the thermal resistance TC is the case temperature EXAMPLE-1 2N3773 NPN Power Transistor Without a Heat Sink


Thermal data

MIN TYP MAX

θJC - - 1,17 °C/W

θJA - - 43,7 °C/W

PMAX is to be derated linearly at a rate of 0,855W/°C which corresponds to 1/θJC . Power derating is usually started at 25°C and ends at TJ max of the device where PMAX =0.

MAXIMUM POWER DISSIPATION

0 25 50 75 100 125 150 175 200

175

150

125

100

75

50

25

0

MA

XIM

UM

C

ON

TIN

UO

US

D

EV

ICE

D

ISS

IPA

TIO

N

(W)

TC CASE TEMPERATURE (°C)

POWER DERATING FACTORIS EQUAL TO

SLOPE = 1/ θJC = -0,855 W/°C

0 25 50 75 100 125

A) Verify that the absolute maximum power rating is 150W. PMAX depends on the maximum junction temperature of 200°C and the device thermal resistance θJC , that is:

P max = T J ( max ) − T C

θ JC

= 200 − 25

1 , 17= 149 , 57W

P M A X

T J m a x

200°C

T C θ

J C

1,17°C/W (max)

θ CA

+ -

+

- T A = 2 5 ° C

42,53°C/W (max)

This maximum power can only be achieved if we mount the transistor on an infinite heat sink whose thermal resistance is zero. This is physically impossible and costly. In practice heat sink thermal resistances can be as low as 0,25 °C/W but the heat sinks become physically quite large.

P M A X

T J m a x

200°C

T C = 2 5 ° C θ

J C

1,17°C/W (max)

θ CA

+ -

+

- T A = 2 5 ° C

42,53°C/W (max)

θ S I N K

= 0

I N F I N I T E

H E A T S I N K

B) What is the maximum power that can be dissipated without a heat sink at ambient temperatures of

+25°C and +50°C?

P max = T J ( max ) − T A θ JC

+ θ CA

= 200 − 25

1 , 17+ 42, 532 = 4 , 0 W

P max = T J ( max ) − T A θ JC + θ CA

= 200 − 50

1 , 17+ 42, 532 = 3 , 43W

P M A X

T J m a x

200°C

T C θ

J C

1,17°C/W (max)

θ CA

+ -

+

- T A = 2 5 ° C

42,53°C/W (max)


C) Determine the junction and case temperatures if the transistor dissipates 2W at an ambient temperature of 35°C - assume that no heat sink is used. Using thermal Ohm's law, ∆ T = P × θ , results are easily obtained - see diagram shown beside.

122,4°C θ J C

1,17°C/W (max)

θ CA

+ -

+

- T A = 3 5 ° C

42,53°C/W (max) 2 W

2 W 2 W

J C

120,06°C

85,06°C

2,34°C

5. THERMAL EQUIVALENT CIRCUIT WITH A HEAT SINK

SILICON

ELECTRICALINSULATOR

EBC

TRANSISTORCASE

COOLING FINS COOLING FINS

COLLECTORCONNECTION

SILICON

EBC

FIRST PATH: JUNCTION TO CASE TO AMBIANT AIR, HIGH RESISTANCE PATH

SECOND PATH: JUNCTION TO CASE TO HEAT SINK TO AMBIANT AIR, LOW RESISTANCE PATH.

FIRST PATH

SECOND PATH SECOND PATH


When the heat sink is added, the case thermal resistance (θCA) is nearly doubled because its lower surface area is lost to the heat sink. If the heat sink area is very large then very little heat will be dissipated through the case and θCA can be ignored. In some heat sink data, θCA is lumped with the heat sink thermal resistance (θSA).

TJ TC TS

TA

PSI

θJC θCS

θSAθCA

INSULATORRESISTANCE

HEAT SINKRESISTANCE

JUNCTION CASE SINK

AMBIANT AIR

HEATSOURCE

PSI

P1

P2

P2

modified

Typical insulator thermal resistance (θθθθCS )

METAL-TO-METAL USING AN INSULATOR

CASE dry H/S compound H/S compound Type

T0-3 0,2°C/W 0,1°C/W 0,36°C/W 3 mil mica

T0-3 0,2°C/W 0,1°C/W 0,28°C/W Anodized Aluminum

TO-66 1,5°C/W 0,5°C/W 0,9°C/W 2 mil mica

TO-220 1,2°C/W 1,0°C/W 1,6°C/W 2 mil mica EXAMPLE-2 2N3773 NPN Power Transistor With Heat Sink A) A 2N3773 power transistor which dissipates a continuous power of 20W is mounted on a heat sink with a 3 mil mica insulator with heat sink compound. Determine the maximum heat sink thermal resistance required if we want to keep the junction temperature at least 60°C below its absolute maximum (to extend its lifespan) and also to keep the heat sink temperature below 80 °C. Assume that the ambient temperature varies from +15°C to +40 °C. Assume natural convection.

TJ TC TS

TA

θJC θCS

θSAθCAHEAT SINK

RESISTANCE

0,36 °C/W1,17 °C/W

170°C MAX 80 °C MAX

20W IGNORE

50W 50W

20W

40°C MAX

T J = T A + P × θ tot

⟨ 140 ⇒ θ tot

⟨ T J max − T A

P = 140 − 40

20= 5 ° C / W

θ SA

= θ tot

− θ JC

− θ CS

= 5 − 1 , 17− 0 , 36⟨ 3 , 47° C / W

T S = T A + P × θ SA

⟨ 80 ⇒ θ SA

⟨ T S max − T A max

P = 80− 40

20= 2 ° C / W

Answer θθθθSA < 2°C/W


B) Assuming that a Wakefield #641-A heat sink is used, determine TJ, TC and TS for an ambient temperature of 40°C when 20W continuous is dissipated. Assume natural convection.

θCA

0,36 °C/W1,17 °C/W

20W IGNORE

20W

40°C

1,9°C/W

WAKEFIELD#641-A

108,6°C

+38°C

-

+ 23,4°C - + 7,2°C - 78°C85,2°C

J C S

A

3 MIL MICA +GREASE

C) Assuming again that a Wakefield #641-A heat sink is used, determine TJ, TC and TS for an ambient temperature of 40°C when 20W is dissipated. Assume that forced-air convection (a fan) is used with an air velocity of 150 FPM (feet per minute).

D) Safe operating area (SOA) The operating limits of IC and VCE are not only limited by PMAX (or TJ max) but they are also limited by ICmax (bonding wire melting if IC too large), VCEO max (avalanche breakdown) and "second breakdown" (current crowding in small parts of emitter leading to hot spot and burning). One should always check if the operating values of IC and VCE are within the SOA of the transistor with enough safety margin. There are two limitations on the power handling ability of a transistor: average junction temperature and second breakdown. Safe operating area curves indicate IC – VCE limits of the transistor that must be observed for reliable operation: i.e., the transistor must not be subjected to greater dissipation than the curves indicate. The data of Figure 7 (beside) is based on TJ(pk) = 200 °C; TC is variable depending on conditions. Second breakdown pulse limits are valid for duty cycles to 10% provided TJ(pk) < 200 °C. At high case temperatures, thermal limitations will reduce the power that can be handled to values less than the limitations imposed by second breakdown.

2N3773 SAFE OPERATING AREA


6. TRANSIENT THERMAL IMPEDANCE - PULSE OPERATION If a power device is operated in a pulse mode (switched ON and OFF) temperature will vary as a function of time because of thermal capacitances involved along with thermal resistances.

The junction temperature of the device will vary as shown below where one is always interested in determining the maximum junction temperature to ensure that it is not excessive.

TJ

TC

0

PD

tim e

T

E

M

P

E

R

A

T

U

R

E

TA

TJ (AVE ) = TC + PD (AVE ) × θJC( )

TJ (MAX ) = TC + PD × Z JC( )( )t

ZJC(t ) = θ JC ×r (t )

TC (AVE ) = TA + PD (AVE ) × θCA

PD(AVE) = PD x D

P W

T

D =T

P W

NORMALIZED THERMAL RESPONSE OF TIP120


EXAMPLE-3 PULSE OPERATION OF TIP120 A TIP120 is mounted directly on a Wakefield 270-AB heat sink (no insulator) with thermal grease. A) A TIP120 is driven by a single 10 ms pulse as shown below. Assume that the heat sink is large enough such that the case temperature does not have time to rise substantially within 10 ms - large time constant. Ambient temperature is 30°C. Determine TJ max, the approximate time constant of the junction to case material and sketch graph of TJ versus t. 10 ms

We can read r(t) = 0,31 at = 10 ms on the transient thermal impedance shown at the bottom of the previous page. (for TIP120)

Z JC( t ) = r ( t ) × θ

JC= 0 , 31× 1 , 92≈ 0 , 6 ° C / W

TA=30°C

ZJC1°C/W

INSULATOR

ZJC (10 ms)

= 0,6°C/W

TS = 30°CTJ max = 60°C

0

10 ms

50W

TC= 30°C

4°C/W

The thermal time constant from junction to case can be obtained from the 0% duty cucle curve: after one τJC, r(t) = (1-e-(t/τ) = 0,632 and we read t = τJC = 75 ms.

+60°C

+30°C

50W

0W

0 10 m s 385 m s

5 τJ C

TJ PD

Let us verify that the load line lies within the SOA curve to ensure safe operation of the transistor.


B) Repeat part A with repetitive pulses at 500 Hz and 20% duty cycle. Assume the same voltage levels (same peak power). For average temperatures we can use the average power and use only the thermal resistances as done with continuous power dissipation.

PAVE = D x PMAX = 0,2 * 50 = 10W.

For maximum TJ we can read r(t) = 0,4 at 0,4 ms with 20% duty cycle, therefore we have: ZJC(t,D)=r(t) x θJC = 0,25 x 1,92 = 0,48°C/W.

Z JC( 0 . 4 ms, 20% ) = 0 , 480

C / W

T J max = 104 0 C

TJ will vary as shown below.

EQUAL AREAS

0

P O W E R

104°C

99,2°C

94,4°C50W

10W AVERAGE

JUNCTION TEMPERATURE AFTER INITIAL TRANSIENT

The above calculations show that TJ max is well below the maximum 200°C specified. After ensuring operation within the FBSOA the device is deemed to operate safely. NOTE: The above calculations assume that the heat sink thermal time constant is large enough such that we can assume a quasi constant case temperature after the initial transient. The average of a function is given by the following expression:

Ave f ( t ) = 1

t 2 − t 1 f ( t )

t 1

t 2

∫ dt ⇒ Ave f ( t ) = 1

T f ( t )

0

T

∫ dt for a periodic function.

Heat Sinks


EXAMPLE-4 Programmable Power Supply A) Determine the number of RFP12P10’s required to handle maximum power dissipation if we want to maintain the transistors’ junction temperature 30oC below the maximum rated value. Assume that ambient temperature ranges from 20 oC to 30 oC and that all transistors are to be mounted on a single heat sink using a 2-mil mica insulator. Also assume a maximum heat sink temperature of 60 oC. Vo of the programmable supply ranges from 0 to 25.5V and IL from 0 to 2.55A.

A1

R4

R5

R6

R7

C1Rse n

V OL TAG E CO N TR OL DA C

L F347

2 00

10 V

2 00

Q 3

Q 1 Q2

2 N2 2 2 2

BIN-1

Vr ef0 .5

+ V o -

28V to 32V

0 TO + 25.5V

IL

RF P1 2P 10 'sO N S IN GL E HE AT S IN K

1 1

R EFV LC +V cc -V e e co m

M SB L SB

DAC 080 0

14

15

1

2

34

5 12

13 16

Iou t

Iou t

R EF

+14V

-1 4V+14 V-1 4V

L O A D

The worst case power dissipation for the MOSFETs is when VDS is maximum which occurs when Vo is 0V and IL = 2.55A max.

55.2155.25.055.232 ×

×−×−==

NIVP DDStotal

Assuming N = 3 MOSFET, we have Ptota l=76.2W max TJ max = 150 oC from data sheets. The insulator thermal resistance is that of a typical TO-220 insulator – see chart on page 6. The maximum heat sink resistance is

WCoSA /394.02.763060 =−⟨θ

( )( ) 83.3

601256.167.12.76

1256.167.12.7660max

=−

+×⟩

⟨+×+=

N

NTJ

We will need 4 power transistors which will each dissipate a maximum power of:

WIVP DDStotal 18.19455.21

455.25.055.232 =×

×−×−==

Pmax76.2W

1.67 oC/W

1.67 oC/W

1.67 oC/W

1.6 oC/W

1.6 oC/W

1.6 oC/W

C

C

CTJ

120 oCmax

θθθθCAHEATSINK

TA 30 oCmax

60 oCmax

TS

Pmax/ N

Pmax/ N

Pmax/ N

Pmax

Heat Sinks


B) Find a suitable Wakefield heat sink and then calculate the maximum heat sink temperature and junction temperatures. I selected a Wakefield 433K from the data shown below – see data sheets at the end for better resolution of the pictures. It has a θSA of 0.28 oC/W with forced convection cooling of 250 LFM.

Pmax76.7W

1.67 oC/W 1.6 oC/WC

1.67 oC/W

1.67 oC/W

1.6 oC/W

1.6 oC/W

C

CTJ

114.2 oCmax

HEATSINK

wakefield433K

ForcedconvectionTA 30 oC

max

51.5oCmax

TS

1.67 oC/W 1.6 oC/WC19.18W

19.18W

19.18W

19.18W

76.7W

0.28oC/W

82.2oCmax

0.2 mil micainsulator

82.2oCmax

82.2oCmax

82.2oCmax

ExtrudedHeat Sinks

All other products, please contact factory for price, delivery, and minimums. G Normally stockedC. Sauriol Rev. 1/27/2003 © Heat Sinks

EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS621 AND 623 SERIES Low-Profile Heat Sinks for All Metal-Case Power Semiconductors

Footprint Thermal Performance at Typical LoadStandard Dimensions Height Mounting Natural Forced WeightP/N in. (mm) in. (mm) Hole Pattern Convection Convection lbs. (grams)621A 4.750 (120.6) x 1.500 (38.1) 0.461 (11.7) (1) TO-3 75°C @ 15W 2.0°C/W @ 250 LFM 0.1000 (45.36)621K 4.750 (120.6) x 1.500 (38.1) 0.461 (11.7) None 75°C @ 15W 2.0°C/W @ 250 LFM 0.1000 (45.36)623A 4.750 (120.6) x 3.000 (76.2) 0.461 (11.7) (1) TO-3 52°C @ 15W 1.5°C/W @ 250 LFM 0.2100 (95.26)623K 4.750 (120.6) x 3.000 (76.2) 0.461 (11.7) None 52°C @ 15W 1.5°C/W @ 250 LFM 0.210O (95.26)

A general purpose yet efficient heat dissipator for TO-3 and virtually all other styles of metal casepower semiconductor package types, the 621 and 623 Series low-profile flat back heat sinks finda wide variety of applications. The central channel between fins measures 1.300 in. (33.0) (min.)

in width, accommodating many types of packages. Mounting hole pattern "A" is predrilled for thestandard TO-3 package. Material: Aluminum Alloy, Black Anodized.

TO-3

MECHANICALDIMENSIONS

621 AND 623 SERIES (EXTRUSION PROFILE 1327)

Dimensions: in. (mm)

NATURAL AND FORCED CONVECTION CHARACTERISTICS

SEMICONDUCTOR MOUNTING HOLES


302 AND 303 SERIES

301 SERIESDimensions: in. (mm)




641 SERIES(EXTRUSION PROFILE 1371)




301/302/303 SERIES Compact Heat Sinks for Dual Stud-Mounted Semiconductor Cases

Outline Mounting Thermal Performance at Typical LoadStandard Dimensions Length “A” Hole (s) Natural Forced WeightP/N in. (mm) in. (mm) Pattern and Number Convection Convection lbs. (grams)

301K 2.000 (50.8) x 2.000 (50.8) 0.750 (19.1) None 70°C @ 15W 2.5°C/W @ 250 LFM 0.0580 (26.31)301M 2.000 (50.8) x 2.000 (50.8) 0.750 (19.1) (1) 10-32UNF, 0.625 in. thread depth 70°C @ 15W 2.5°C/W @ 250 LFM 0.0580 (26.31)301N 2.000 (50.8) x 2.000 (50.8) 0.750 (19.1) (1) 1⁄4 -28UNF, 0.625 in. thread depth 70°C @ 15W 2.5°C/W @ 250 LFM 0.0580 (26.31)302M 2.000 (50.8) x 2.000 (50.8) 1.500 (38.1) (1) 10-32UNF, 0.625 in. thread depth 50°C @ 15W 1.8°C/W @ 250 LFM 0.1330 (60.33)302MM 2.000 (50.8) x 2.000 (50.8) 1.500 (38.1) (2) 10-32UNF, 0.625 in. thread depth 50°C @ 15W 1.8°C/W @ 250 LFM 0.1330 (6033)302N 2.000 (50.8) x 2.000 (50.8) 1.500 (38.1) (1) 1⁄4 -28UNF, 0.625 in. thread depth 5O°C @ 15W 1.8°C/W @ 250 LFM 0.1330 (60.33)302NN G 2.000 (50.8) x 2.000 (50.8) 1.500 (38.1) (2) 1⁄4 -28UNF, 0.625 in. thread depth 50°C @ 15W 1.8°C/W @ 250 LFM 0.1330 (60.33)303M 2.000 (50.8) x 2.000 (50.8) 3.000 (76.2) (1) 10-32UNF, 0.625 in. thread depth 37°C @ 15W 1.3°C/W @ 250 LFM 0.2680 (121.56)303MM 2.000 (50.8) x 2.000 (50.8) 3.000 (76.2) (2) 10-32UNF, 0.625 in. thread depth 37°C @ 15W 1.3°C/W @ 250 LFM 0.2680 (121.56)303N G 2.000 (50.8) x 2.000 (50.8) 3.000 (76.2) (1) 1⁄4 -28UNF, 0.625 in. thread depth 37°C @ 15W 1.3°C/W @ 250 LFM 0.2680 (121.56)303NN 2.000 (50.8) x 2.000 (50.8) 3.000 (76.2) (2) 1⁄4 -28UNF, 0.625 in. thread depth 37°C @ 15W 1.3°C/W @ 250 LFM 0.2680 (121.56)

The large fin area in minimum total volume provided by the radial design of the 301/302/303Series offers maximum heat transfer efficiency in natural convection. All types are availablewith one tapped mounting hole for rectifiers and other stud-mounting semiconductors; the

302 and 303 Series offer maximum cost savings with dual mounting locations (“MM” and“NN” mounting hole patterns) for two stud-mount devices. Material: Aluminum Alloy, BlackAnodized.

STUD-MOUNT

641 SERIES Maximum Performance Natural Convection Heat Sink for all Metal-Case Semiconductors

Outline Mounting Thermal Performance at Typical LoadStandard Dimensions Height Hole Natural Forced WeightP/N in. (mm) in. (mm) Pattern Convection Convection lbs. (grams)

641A G 4.125 (104.8) x 3.000 (76.2) 1.000 (25.4) (1) TO-3 36°C @ 15W 0.9°C/W @ 250 LFM 0.2900 (131.54)641K G 4.125 (104.8) x 3.000 (76.2) 1.000 (25.4) None 36°C @ 15W 0.9°C/W @ 250 LFM 0.2900 (131.54)

Available with a standard TO-3 mounting hole pattern predrilled for cost-effective mounting inlimited-height applications, the 641 Series provides maximum performance in natural convec-tion with an optimized heat sink surface area. The 641K type with an open channel area of

1.300 in. (33.0) and no predrilled mounting holes can be adapted to meet mounting require-ments for most metal case power semiconductor types. Material: Aluminum Alloy, BlackAnodized.

TO-3

A K

K

SERIES301302303

M

A K

N

ExtrudedHeat Sinks

G Normally stocked C. Sauriol Rev. 1/27/2003 © Heat Sinks

413/421/423 SERIES Low-Height Double-Surface Heat Sinks for TO-3 Case Styles and Diodes

Space-saving double surface 413, 421, and 423 Series utilize finned surfacearea on both sides of the power semiconductor mounting surface to providemaximum heat dissipation in a compact profile. Ready to install on popularpower components in natural and forced convection applications. Apply

Wakefield Type 126 silicone-free thermal compound or Wakefield DeltaPad™interface materials for maximum performance. Material: Aluminum Alloy, BlackAnodized.

TO-3; DO-5; Stud-Mount

EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS401 AND 403 SERIES Double-Surface Heat Sinks for TO-3 Case Styles TO-3; Stud-Mount

With fins oriented vertically in cabinet sidewall applications, 401 and 403 Series heat sinksare recommended for critical space applications where maximum heat dissipation is requiredfor high-power TO-3 case styles. Forced convection performance is also exemplary with thesedouble surface fin types. Semiconductor mounting hole style “F” offers a single centered

0.270 in. (6.9)-diameter mounting hole (with a 0.750 in. (19.1)-diameter area free of anodize)for mounting stud-type diodes and rectifiers. Hole pattem “V" available upon request.Material: Aluminum Alloy, Black Anodized.

Standard Width Overall Dimensions Height Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattem Natural Convection Forced Convection lbs. (grams)

401A G 4.750 (120.7) 1.500 (38.1) 1.250 (31.8) (1) TO-3 80°C @ 30W 1.5°C/W @ 250 LFM 0.1500 (68.04)401F 4.750 (120.7) 1.500 (38.1) 1.250 (31.8) 0.270 in. (6.9)-Dia Hole 80°C @ 30W 1.5°C/W @ 250 LFM 0.1500 (68.04)401K G 4.750 (120.7) 1.500 (38.1) 1.250 (31.8) None 80°C @ 30W 1.5°C/W @ 250 LFM 0.1500 (68.04)403A G 4.750 (120.7) 3.000 (76.2) 1.250 (31.8) (1) TO-3 55°C @ 30W 0.9°C/W @ 250 LFM 0.3500 (158.76)403F G 4.750 (120.7) 3.000 (76.2) 1.250 (31.8) 0.270 in. (6.9)-Dia Hole 55°C @ 30W 0.9°C/W @ 250 LFM 0.3500 (158.76403K G 4.750 (120.7) 3.000 (76.2) 1.250 (31.8) None 55°C @ 30W 0.9°C/W @ 250 LFM 0.3500 (158.76)

MECHANICAL DIMENSIONS



403 SERIES

A F K V

401 SERIES

401 AND 403 SERIES(EXTRUSION

PROFILE 1024)

413 SERIES(EXTRUSION

PROFILE 2276


PROFILE 1025)

SERIES413421


A F K V

Nominal DimensionsStandard Width Length Height “A” Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattern Natural Convection Forced Convection lbs. (grams)

413A 4.750 (120.7) 3.000 (76.2) 1.875 (47.6) (1) TO-3 72°C @ 50W 0.85°C/W @ 250 LFM 0.6300 (285.77)413F 4.750 (120.7) 3.000 (76.2) 1.875 (47.6) 0.270 in. (6.9)-Dia Hole 72°C @ 50W 0.85°C/W @ 250 LFM 0.6300 (285.77)413K G 4.750 (120.7) 3.000 (76.2) 1.875 (47.6) None 72°C @ 50W 0.85°C/W @ 250 LFM 0.6300 (285.77)421A 4.750 (120.7) 3.000 (76.2) 2.625 (66.7) (1) TO-3 58°C @ 50W 0.7°C/W @ 250 LFM 0.6300 (285.77)421F 4.750 (120.7) 3.000 (76.2) 2.625 (66.7) 0.270 in. (6.9)-Dia Hole 58°C @ 50W 0.7°C/W @ 250 LFM 0.6300 (285.77)421K G 4.750 (120.7) 3.000 (76.2) 2.625 (66.7) None 58°C @ 50W 0.7°C/W @ 250 LFM 0.6300 (285.77)423A 4.750 (120.7) 5.500 (140.2) 2.625 (66.7) (1) TO-3 47°C @ 50W 0.5°C/W @ 250 LFM 1.1700 (530.71)423K G 4.750 (120.7) 5.500 (140.2) 2.625 (66.7) None 47°C @ 50W 0.5°C/W @ 250 LFM 1.1700 (530.71)






ExtrudedHeat Sinks


EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS431 AND 433 SERIES High-Performance Heat Sinks for 30-100W Metal Power Semiconductors

Need maximum heat dissipation from a TO-3 rectifier heat sink inminimum space? The Wakefield 431 and 433 Series center chan-

nel double-surface heat sinks offer the highest performance-to-weight ratio for minimum vol-ume occupied for TO-3, diode, and stud-mount metal power semiconductors in the 30- to

100-watt operating range. Additional interface resistance reduction for maximized overall per-formance can be achieved with proper application of Wakefield Type 126 silicone-free thermalcompound. Material: Aluminum Alloy, Black Anodized.

TO-3; Stud-Mount

TO-3

Nominal DimensionsStandard Width Length “A” Height Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattern Natural Convection Forced Convection lbs. (grams)431K 4.750 (120.7) 3.000 (76.2) 3.000 (76.2) None 55°C @ 5OW 0.40°C/W @ 250 LFM 0.7800 (353.81)433K G 4.750 (120.7) 5.500 (139.7) 3.000 (76.2) None 42°C @ 5OW 0.28°C/W @ 250 LFM 1.4900 (675.86)


MECHANICAL DIMENSIONSSERIES

431433

K


SEMICONDUCTORMOUNTING HOLE

431 AND 433SERIES

(EXTRUSIONPROFILE 2726)

435 SERIES Lightweight Quadruple Mount Heat Sink for TO-3 Case StylesNominal Dimensions

Standard Width Length Height Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattern Natural Convection Forced Convection lbs. (grams)435AAAA 4.250(108.0) 5.500(139.7) 4.300(109.2) (4) TO-3 37°C @ 50W 0.38°C/W @ 250 LFM 1.1500 (521.64)

54°C @ 80W 0.24°C/W @ 600 LFM

MECHANICAL DIMENSIONSDimensions: in. (mm)


SEMICONDUCTORMOUNTING HOLES

AAAA

441 SERIES High-Performance Natural Convection Heat Sinks for Rectifiers and Diodes Stud-Mount

Nominal DimensionsStandard Width Length Height Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattern Natural Convection Forced Convection lbs. (grams)441K G 4.750 (120.7) 5.500 (139.7) 4.500 (114.3) None 34°C @ SOW 0.30°C/W @ 250 LFM 1.9700 (893.59)

47°C @ 80W 0.19°C/W @ 600 LFM

Designed for vertical mounting within a power supply enclosureor equipment cabinet without forced airflow available. This

Wakefield 441 Series heat sink will dissipate up to 100 watts efficiently in natural convectionwith a maximum 55°C heat sink temperature rise above ambient. When applied in a forced

convection environment, the 441K Type will achieve thermal resistance of 0.18°C/W (sink toambient) at 1000 LFM. Supplied with no predrilled device mounting hole pattern. Material:Aluminum Alloy, Black Anodized.

This lightweight high-performance heat sink is designed tomount and cool efficiently one to four TO-3 style metal case

power semiconductors. The Type 435AAAA is the standard configuration available from stock,predrilled for mounting four TO-3 style devices. Increased performance can be achieved with

the proper selection and installation of a Wakefield Type 175 DeltaPad Kapton™ interfacematerial for each power semiconductor or, for maximum reduction of case-to-sink interfaceloss, the application of Wakefield Type 126 silicone-free thermal compound. Material:Aluminum Alloy, Black Anodized.


PROFILE 4226)

MECHANICAL DIMENSIONS NATURAL AND FORCED CONVECTION CHARACTERISTICS


441 SERIES (EXTRUSION

PROFILE 1273)

K


ExtrudedHeat Sinks


EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS465 AND 476 SERIES High-Power Heat Sinks for Medium Hex-Type Rectifiers and Diodes Stud-Mount

Wakefield Engineering has designed four standard heat sink types for ease of installation andefficient heat dissipation for industry standard hex-type rectifiers and similar stud-mountpower devices: 465, 476, 486, and 489 Series. The 465 and 476 Series shown here are

designed for 1.060 in. Hex (465 Type) and 1.250 in. Hex (476 Type). The 476W Type is avail-able predrilled for an 0.765 in. (19.4) dia, mounting hole, Material: Aluminum Alloy, Blackanodized.

Nominal DimensionsStandard Width Length Height Hex Style Mounting Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Type Hole Pattern Natural Convection Forced Convection lbs. (grams)

465K 4.000 (101.6) 5.000 (127.0) 4.000 (101.6) 1.060 in. Hex None 38°C @ 5OW 0.27°C/W @500 LFM 1.9300 (875.45)476K 5.000 (127.0) 6.000 (152.4) 5.000 (127.0) 1.250 in. Hex None 25°C @ 5OW 0.19°C/W @500 LFM 2.8200(1279.15)476W 5.000 (127.0) 6.000 (152.4) 5.000 (127.0) 1.250 in. Hex 0.765 in. 25°C @ 5OW 0.19°C/W @500 LFM 2.8000(1270.08)

(19.4)Dia.Center Mount


SEMICONDUCTORMOUNTING HOLES

K W

476 SERIES (EXTRUSION PROFILE 1245)


486 AND 489 SERIES Heat Sinks for High-Power Hex-Type Rectifiers and Diodes Stud-Mount

Nominal DimensionsStandard Width Length Height Hex Style Mounting Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Type Hole Pattern Natural Convection Forced Convection lbs. (grams)

486K G 6.250 (158.8) 6.000 (152.4) 6.250 (158.8) 1.750 in. Hex None 24°C @ 50W 0.20°C/W @250 LFM 4.2100 (1909.66)86°C @ 250W 0.13°C/W @500 LFM

489K G 6.250 (158.8) 9.000 (228.6) 6.250 (158.8) 1.750 in. Hex None 19°C @ 50W 0.15°C/W @250 LFM 6.1400 (2785.10)75°C @ 250W 0.10°C/W @500 LFM

These two heat sink types accept industry standard 1.750 in. (44.5) hex-type devices formounting and efficient heat dissipation. Each type is provided with a 1.750 in. (44.5) x 2.000

in. (50.8) area on the semiconductor base mounting surface which is free of anodize.Material: Aluminum Alloy, Black Anodized.


KSEMICONDUCTOR MOUNTING HOLE


486 AND 489 SERIES(EXTRUSION

PROFILE 1541)Dimensions: in. (mm)



SERIES

486489

ExtrudedHeat Sinks


EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS490 SERIES King Size Heat Sinks for High-Power Rectifiers

The 490 Series can be used to mount a single high-power rectifier or a grouping of smallerpower devices. The semiconductor device mounting surface is free of anodize on the entiresurface on one side only; finish overall is black anodize. Use Type 109 mounting brackets(see accessories section) for mounting to enclosure wall and for electrical isolation. The

anodize-free mounting surface is milled for maximum contact area. The 490 Series Can alsobe drilled for mounting and cooling IGBTs and other isolated power modules. Material:Aluminum Alloy, Black Anodized.

GENERAL PURPOSE

Nominal DimensionsStandard Width Length “A” Height Semiconductor Thermal Performance at Typical Load WeightP/N in. (mm) in. (mm) in. (mm) Mounting Hole Pattern Natural Convection Forced Convection lbs. (grams)

490-35K 9.250 (235.0) 3.500 (88.9) 6.750 (171.5) None 84°C @ 20OW 0.18°C/W @ 600 LFM 3.2400(1469.66)490-6K G 9.250 (235.0) 6.000 (152.4) 6.750 (171.5) None 60°C @ 20OW 0.13°C/W @ 600 LFM 5.4700(2481.19)490-12K G 9.250 (235.0) 12.000 (304.8) 6.750 (171.5) None 45°C @ 20OW 0.09°C/W @ 600 LFM 10.62 (4817.23)



NATURAL AND FORCEDCONVECTION CHARACTERISTICS



PERFORMANCE, LOW PROFILE HEAT SINKS FOR POWER MODULES & IGBT’S394, 395, 396 SERIES

Thermal Resistance at Typical LoadOverall Dimensions: in. (mm) Device Base Natural Forced

Standard Length Height Width Mounting Area Base Mounting Convection (Øsa)(1) Convection (Øsa)P/N in. (mm) in. (mm) in. (mm) (mm) Holes (°C/W) (°C/W @ 500 LFM)

394-1AB 3.000 (76.2) 1.500 (38.1) 5.000 (127.0) 101 x 76 4 1.85 0.90394-2AB 5.500 (139.7) 1.500 (38.1) 5.000 (127.0) 101 x 139 6 1.51 0.60395-1AB 3.000 (76.2) 2.500 (63.5) 5.000 (127.0) 50 x 76 4 1.10 0.50395-2AB 5.500 (139.7) 2.500 (63.5) 5.000 (127.0) 50 x 139 6 0.90 0.32396-1AB 3.000 (76.2) 1.380 (35.1) 5.000 (127.0) 50 x 76 4 1.85 1.07396-2AB 5.500 (139.7) 1.380 (35.1) 5.000 (127.0) 50 x 139 6 1.51 0.64Note: 1.Thermal resistance values shown are for black anodized finish at 50°C rise above ambient.









ExtrudedHeat Sinks


SERIES 517, 527, 518 AND 528 Heat Sinks for “Half Brick” DC/DC Converters

Thermal PerformanceFootprint Natural Convection Forced Convection

Standard Dimensions Height Fin Number Power Dissipation (Watts) Thermal ResistanceP/N in. (mm) in. (mm) Orientation of Fins 60°C Rise Heat Sink to Ambient at 300 ft/min517-95AB 2.28 (57.9) x 2.40 (61.0) 0.95 (24.1) Horizontal 8 11W 2.0 °C/W527-45AB 2.28 (57.9) x 2.40 (61.0) 0.45 (11.4) Horizontal 11 7W 3.2 °C/W527-24AB 2.28 (57.9) x 2.40 (61.0) 0.24 (6.1) Horizontal 11 5W 5.8 °C/W518-95AB 2.40 (61.0) x 2.28 (57.9) 0.95 (24.1) Vertical 8 11W 2.0 °C/W528-45AB 2.40 (61.0) x 2.28 (57.9) 0.45 (11.4) Vertical 11 7W 3.2 °C/W528-24AB 2.40 (61.0) x 2.28 (57.9) 0.24 (6.1) Vertical 11 5W 5.8 °C/WMaterial: Aluminum, Black Anodized.

Keep your "half brick" size AT&T and Computer Products power modules cool with these effi-cient black anodized aluminum heat sinks made for natural or forced convection applications.To include four M3 x 8mm Phillips head SEM attachment screws, add an “M” suffix to stan-

dard part number. To specify factory applied Deltalink IV thermal interface material, add an“S4” suffix to standard part number. Deltalink IV is a non-insulating graphite based materialused as a clean, thermally efficient alternative to thermal grease.

TO-220 and TO-218

MECHANICAL DIMENSIONS 517, 527, 518 AND 528 SERIES

PRODUCT DESIGNATION 517/527 SERIES DIMENSIONS 518/528 SERIES DIMENSIONS

EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS

Standard Description For Use with Series Mounting Hipot Rating WeightP/N Hardware Material (VAC) lbs. (grams)

103 Spool-shaped insulator 300, 400, 600, 111, 113 #6-32 screw Teflon 1500 0.00012 (0.05)107 Spool-shaped insulator 300, 400, 600, 111, 113 #6-32 screw, nut Teflon 5000 0.0034 (1.54)

100 SERIES Teflon Mounting Insulators

MOUNTING HARDWARE FOR EXTRUDED HEAT SINKS

103 SERIES 107 SERIES


ExtrudedHeat Sinks


HIGH FIN DENSITY HEAT SINKS FOR POWER MODULES, IGBTs, RELAYSHeight Thermal Resistance (5)

(Øsa) at Typical LoadStandard Catalog P/N(5) Milled Base (1) Nonmilled Base (2) Natural ForcedMilled Nonmilled Base Width Length (“M Series”) (“U” Series) Convection(3) Convection(4)

Base(1) Base(2) in. (mm) in. (mm) in. (mm) in. (mm) (°C/W) (°C/W @ 100 CFM)510-3M 510-3U 7.380 (187.452) 3.000 (76.2) 3.106 (78.9) 3.136 (79.7) 0.56 0.088510-6M 510-6U 7.380 (187.452) 6.000 (152.4) 3.106 (78.9) 3.136 (79.7) 0.38 0.070510-9M 510-9U 7.380 (187.452) 9.000 (228.6) 3.106 (78.9) 3.136 (79.7) 0.29 0.066510-12M G 510-12U G 7.380 (187.452) 12.000 (304.8) 3.106 (78.9) 3.136 (79.7) 0.24 0.062510-14M G 510-14U G 7.380 (187.452) 14.000 (355.6) 3.106 (78.9) 3.136 (79.7) 0.21 0.059511-3M 511-3U 5.210 (132.33) 3.000 (76.2) 2.350 (59.7) 2.410 (61.2) 0.90 0.120511-6M 511-6U 5.210 (132.33) 6.000 (152.4) 2,350 (59.7) 2.410 (61.2) 0.65 0.068511-9M 511-9U 5.210 (132.33) 9.000 (228.6) 2.350 (59.7) 2.410 (61.2) 0.56 0.060511-12M 511-12U 5.210 (132.33) 12.000 (304.8) 2.350 (59.7) 2.410 (61.2) 0.45 0.045512-3M 512-3U 7.200 (182.88) 3.000 (76.2) 2.350 (59.7) 2.410 (61.2) 0.90 0.120512-6M 512-6U 7.200 (182.88) 6.000 (152.4) 2.350 (59.7) 2.410 (61.2) 0.65 0.068512-9M 512-9U 7.200 (182.88) 9.000 (228.6) 2.350 (59.7) 2.410 (61.2) 0.56 0.060512-12M 512-12U 7.200 (182.88) 12.000 (304.8) 2.350 (59.7) 2.410 (61.2) 0.45 0.045

MECHANICAL DIMENSIONS NATURAL AND FORCED CONVECTION CHARACTERISTICS

Series A B C Flatness

511-U 512-U 0.250 (6.4) 2.410 (61.2) 0.372 (9.4) 0.006 in./in. (0.15 mm/mm)

511-M 512-M 0.220 (5.6) 2.350 (59.7 0.342 (8.7) 0.002 in./in. (0.05 mm/mm)


Series A B Flatness

510-U 0.216 (5.5) 3.136 (79.7) 0.006 in./in. (0.15 mm/mm)

510-M 0.165 (4.2) 3.106 (78.9) 0.002 in./in. (0.05 mm/mm)

510 SERIES 510 Series (Extrusion Profile 5113)

511 Series (Extrusion Profile 6438-1)511 AND 512 SERIES 512 Series (Extrusion Profile 6438-2)

392 SERIES HIGH PERFORMANCE HEAT SINKS FOR POWER MODULES, IGBTs AND SOLID STATE RELAYSThermal Resistance at Typical Load

Standard P/N, Finish Natural ForcedBlack Gold Length Convection (Øsa) Convection (Øsa) Weight

Anodized Iridite in. (mm) (°CW) (°CW) lbs. (grams)3 9 2 - 1 2 0 A B 3 9 2 - 1 2 0 A G 4.725 (120.0) 0 . 5 0 0.16 @ 100 CFM 4.452 (2019.43)392-180AB G 392-180AG G 7.087 (180.0) 0 . 4 3 0.11 @ 100 CFM 6.636 (3010.09)392-300AB G 392-300AG G 11.811 (300.0) 0 . 3 3 0.08 @ 100 CFM 1O.420 (4726.51)

392 SERIES (EXTRUSION

PROFILE 5658)

510, 511 AND 512 SERIES

N o t e s :1. Precision-milled base for maximum heat transfer

p e rformance (flatness 0.002 in./in.)

2. Nonmilled base flatness: 0.006 in./in.3. Natural convection heat dissipation for distributed heat

s o u rces at 50°C rise.

4. F o rced convection heat dissipation for distributed heats o u rces at 100 cubic feet per minute, shrouded condition.

5. Standard models are provided without finish.

NATURAL AND FORCED CONVECTION CHARACTERISTICSMECHANICAL DIMENSIONS


N AT U R A LC O N V E C T I O N

392-120 (1 MOD)392-180 (1 MOD)392-300 (1 MOD)392-300 (3 MOD)

F O R C E DC O N V E C T I O N

392-120 (1 MOD)392-120 (3 MOD)392-180 (1 MOD)392-180 (3 MOD)392-300 (3 MOD)

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